Heretofore it has been difficult to provide a die mold for casting investment type patterns of irregular shapes since the arcuate surfaces of such shapes lay or extend in non-parallel relation and thus are disposed at different angles, and removal of the defining mold sections defining the mold cavity for the formed pattern presents considerable problems in the design of the mold. This especially becomes a problem when the investment type casting pattern includes a plurality of relatively close side-by-side vanes or blades connected by end shroud portions, so that removal of the investment-type pattern after it has been molded, from the die mold, has been extremely difficult or not feasible. The usual prior art molds for forming multi-vane investment casting patterns are not satisfactory and generally result in interference between movable die mold sections defining the pattern cavities and the formed pattern, during disassembly of the die mold to remove the pattern from the mold.
U.S. Pat. No. 4,073,609 issued Feb. 14, 1978 to John R. Petrenchik and entitled Apparatus for Molding Irregular Shapes discloses a mold which includes swing lever block portions for facilitating movement of the die mold sections defining in part a casting pattern, for removal of the casting pattern from the die mold. However, such apparatus is not feasible especially when attempting to form a casting pattern of irregular shape which includes a plurality of irregular shaped blades or vanes disposed in generally spaced but side-by-side extending relationship.